Here's my setup I'm planning on putting together. Keep in mind the tent will be mind the tent is in a building that is climate controlled to 44 degrees fahrenheit. The tent will be a 3' by 3' by 6' high. I'm going to put the tent up against a wall and put some rigid foam insulation around it on 3 sides and underneath. The door side will probably have a blanket or something draped over it but I figure I'm going to have the venting and heat come in there and want to have access to get it without moving a bunch of shit. The heating is going to be the hardest part but right now I plan on putting the tent next to the furnace which will give me a little heat coming off of it also which will help. I'm going to leave some vents open around the tent for some passive venting but don't want too much cold air coming in. I have two ways planned for heat. I think I'm going to drill a 4 inch hole off of the furnace outlet and take a 4 inch dryer vent into the tent for some heat. Should give me a good boost in temperature in the tent I just need to bring the heat in where it doesn't fry the plants or leaves. For external heat I'm thinking I want to run a small ceramic heater on the outside of the tent with a 4 inch tube going int the tent. Something like this-https://www.amazon.com/Blu7ive-Portable-Personal-Oscillation-Protection/dp/B07JMZPJLZ/ref=as_sl_pc_tf_til?tag=-20&linkCode=w00&linkId=&creativeASIN=B07JMZPJLZ I'm thinking this over the oil filled electric heater because the tent is going to be tight on the inside with 4 plants. I also need to make sure I put the heat where it doesn't damage the plants. I'm thinking of controlling the heater with this type of thermostat device which I will also use as an exhaust temperature controller if it gets to warm when lights are on. This device will be connected to the heater to turn on if the temperature gets below say 65 degrees. I will also have a discharge fan at the top of the tent that will blow hot air out when if the temperature gets above say 85 degrees. I'll put the pbe on the thermostat controller somewhere in the middle of the tent so it gets a good reading. I'm going to probably use an 4 inch internal blower and charcoal filter inside the tent that will just recirculate and move the air around. Might not use the carbon filter at first until the plants start to produce odor. I think this will keep the air moving around inside the tent well and scrub the air. For lights I think I'm going to go a 315 watt cmh light with a 3100 k bulb like this. I think this is going to be a better option over the timber led light I can get my buddy. The led is 400 watts and will probably not create as much heat as the cmh bulb. I think the cmh bulb might be better for the plants and I imagine I could use it for veg and flower. Obviously the lights will be on a timer as i'll be using photo plants in soil. One thing I'll have to do is monitor the humidity and have to change things up it I have a problem. What should be the optimum humidity in my grow environment? I'm afraid a combination of the low humidity in the winter months and heated air from the heat, will make it too dry in the tent. Just have to wait and see. What would be the best way to add humidity to the tent? I know it gets really dry in my house without a humidifier. Let me know your thoughts and recommendations. I'm new to the indoor growing world and want to avoid as many problems as I can. Thanks in advance.
All to often the need to have a high CFM (cubic feet per minute) exhaust fan means such rapid air exchange in the tent to control the heat that you can't keep the humidity up no matter how you try. I grow in the desert southwest and my humidity can drop to single numbers and the plants just keep on rocking along. I've seen people fight to keep it up with a humidifier and wet towels and buckets of water and it just doesn't work unless the tent or room is a sealed system. BNW
Your setup sounds solid. Don’t let low humidity talk you out of it. If that’s the biggest problem you run into you’re golden.